Nano Fe3o4 Improved the Electron Donating Capacity of Dissolved Organic Matter During Sludge Composting

Abstract

The effect of Fe3O4 nanoparticles (Fe3O4 NPs) on the electron transfer process in aerobic composting systems has never been reported. In this paper, it was demonstrated that Fe3O4 NPs could improve the redox performance and electron donating capacity (EDC) of DOM during sludge composting. The addition of Fe3O4 NPs had no effect on the fluorescence components of DOM, but accelerated the formation of fulvic acid-like substances in DOM at the initial stage of composting, promoted the conversion of organic matter to humic acid-like substances, and improved the aromatic condensation degree of DOM at the later stage of composting, which was conducive to compost maturation. The increase in EDC of DOM was closely related with the phenolic group in DOM, and significantly affected by quinone groups and the aromatization degree of DOM.

Keywords: compost, sludge, Fe3O4 nanoparticles, electron transfer capacity, humification